Part of exchange gleaned from vocal board row (5-2)
I believe the answer is:
trade-in
'part of exchange' is the definition.
(I've seen this before)
'gleaned from vocal board row' is the wordplay.
I cannot quite understand how this works, but
'from' could be 'in' (I've seen this in other clues) and 'in' is located in the answer.
The remaining letters 'trade' is a valid word which might be clued in a way I don't understand.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for trade-in that I've seen before include "Article used in part payment for another" , "Older article used in part payment to retailer" , "Something used in part exchange" , "Old item given in part payment for a new one" , "I daren't (anag)" .)